1. Field of the Invention
The present invention relates to an arrangement for am image scanning unit comprising a semiconductor package so arranged as to generate electrical signals corresponding to an image incident upon the light-sensitive surface of the package and so arranged as to be connected by soldering to a circuit board, an optical system arranged in a holder for projecting the image to be scanned onto the aforementioned light-sensitive surface, a mounting plate positioned between the semiconductor package and the circuit board, and devices for joining together the holder and the mounting plate and for ensuring correct mutual alignment between the semiconductor package and the optical system.
2. Description of the Related Art
An arrangement of this kind is previously disclosed through U.S. Pat. No. 4,594,613. The mounting plate is attached in this case to the holder for the optical system by means of screws and pins, which project outwards from the holder and interact with holes in the mounting plate in order to ensure the desired alignment between the semiconductor package and the optical system. The previously disclosed arrangement has a comparatively bulky construction and uses many detail components which demand a relatively long assembly time; in order to be able to fix the holder to the mounting plate with screws, or vice versa, openings are also required in the actual circuit board. Ensuring that the holder is correctly aligned relative to the semiconductor package, as briefly described above, means that the accuracy of the alignment may be jeopardized.